1. Field of the Invention
This invention related to a two-way communication sheet in the form of double post cards, double letter sheet, or the like for use in communicating under cover written information and the like which should be protected from disclosure.
2. Describtion of Background Art
Hitherto, a commercially available double post card of the type which is shown in FIG. 10 has been known as a medium for two-way communication.
Such post card, as generally shown in (a) and (b) of that figure, comprises a first sheet portion 1 for writing by original sender and a second sheet portion 2 for writing in reply, the two sheet portions being connected in series. Further, the second sheet portion is intended to be preprinted with the name and address of the reply receiver. In this way, the double post card is mainly intended to serve for the convience of the replier by prepaying postage and reducing the trouble of the replier in reply writing by preaddressing at or before the time of the double post card being forwarded. However, as can be seen from (c) and (d) of the figure, such double post card is not intended to prevent the content of the communication from exposure, it being simply folded double without having the first and second sheet portions 1, 2 sticked together by pasting or otherwise when it is initially sent, as well as when it is sent for reply.